You may be able to get even 3 months warranty on the van which will give you a few weeks to notice any faults which you might miss on your initial inspection. You might meet others on the sight who will know some history on the van and might be happy to give you some tips on what to look out for. Check that everything works eg. the boiler, fire, cooker,shower etc. Good luck and hope it works out for you.

This one of my main fears, as the water has been drawn down I cannot test everything, I am currently waiting for a call back from the site owner to discuss this.